Off-bottom drill stem tester



AAprxl 4, 1961 M. E. TRUE oFF-BOTTOM DRILL sTEM TESTER Filed June 2, 1958 INVENTOR. MARTIN E. TRUE,

BY /E FIG. 2,

United guitares Patent DFF-BOTTOM DRILL STEM TESTER Martin E. True, Houston, Tex., assignor, by mesne assignments, to `lersey Production Research Company, Tulsa, Okla., a corporation of Delaware Filed June 2, 1958, Sel'. No. 739,283

6 Claims. (Cl. 175--233) The present invention is directed to a drill stern tester. More particularly, the present invention is directed to a drillA stem tester embodying a wire line retrievable sampling assembly. ln its more particular aspects, the invention is directed to an off-bottom drill stem tester embodying a retrievable sample chamber and which is suitable for use with the drill stem in the Well bore.

The present invention may be briefly described as an olf-bottom drill stem tester which comprises a hollow drill stem having a drill bitattached to its lower end and provided with an internal supporting means in the hollow drill stem. Arranged on the exterior surface of the hollow drill stem are spaced apart inflatable packers. The drill stem is provided with a port between the spaced apart packers which communicates the exterior of the drill stern with the interior of the drill stem. In the walls of the drill stern are longitudinally extending passageways which iluidly communicate the interior of the spaced apartl packers with the interior of the drill stem. l

A piston assembly is slidably mounted in the drill stern and is movable from a first to asecond position and vice versa to open and close the longitudinally extending passageways to inflate and deflate the spaced apart packers by fluid pressure. l

Retrievably arranged within the drill stem on a supporting means is a sampling assembly having an inner bore communicating with a valved sample chamber. The assembly is spaced away from the inner wall of the drill stem to provide an annular space and carries spaced apart sealing means whichV are engageable with the inner wall of the drill stem above and below the port to isolate the annular space. A lirst passageway in the retrievable assembly fluidly communicates the inner bore Ywith the isolated annular space. A valve assembly arranged with` in the inner bore fluidly communicates with theV annular space through a second passageway in the retrievable sampling assembly. The piston assembly is adapted to movefrom .a first toasecon'd position on imposition of a lirst predetermined fluid `pressure on the piston assembly to inflate the spaced apant packers and the valve assembly in openable onimposition of a second predetermined vfluid pressure greater than the rstprevalved port below the upper of the spaced apart packers iiuidly communicatingvwith the exterior `of the hollow drill l stern toallow relief of pressure from the space between the packers above an excessive value. The relief of pres* sure may be accomplished by suitably providing a checlt valve in the port communicating with' the by-pass conduit in the space between the packers.

'The sample chamber may suitablyl have a valve member arranged in the-innergbore adjacent the sample charnto admit fluid to the sample chamber, this valve member` being a spring operated valve which will open to allow flow into the valved chamber but which resists ow from the chamber back into the inner bore.

The valve assembly of the drill stem tester of the present invention suitably comprises a valve stem, a valve seating member, a pin member, and a spring member, the spring member and the pin member urging the valve stem against the valve seating member into inner bore closing position.

The piston assembly suitably comprises a piston formed by a slidable sleeve and spring means, the piston being provided with an annular sealing member and the spring means urging the piston into sealing engagement with a sealing surface in the drill stem. The present invention is quite advantageous and useful in that formations pierced by a drill stem having a drill bit on its lower end may be suitably tested to determine Whether or not valuable hydrocarbons are contained in the formations. Moreover, the present invention is quite advantageous in that samples may be obtained from the formation withoutrernoving the drill stem from the well bore by virtue of employing a retrievable sampling assembly.

In addition, the device of the present invention is quite useful and advantageous in that .the arrangement provides for the off-bottom drill stem tester being set at any level in the well bore. Additionally, the well bore fluid entrapped below the set point gives a piston elfect to the lower of the two Vpackers such that the drill stem between the packers assumes a columnar loading to assist the upper packer to support the overburden of the hydrostatic head of drilling fluid. In short, the present invention is quite advantageous and useful in obtaining samples at any levelV in a drilling well without removing the drill stem.

The invention will be further illustrated b y reference to the drawings in which:

Fig. 1 is an elevational view of the device of the' l of Fig. l; and

ber and openable ,runder fluid `pressure inthe inner lbore Fig. 3 is a sectional view taken-along the line 3 3 of Fig. 1.

Referring now to the drawings, numeral 11 designates a Well bore being drilled by a drill stem 12 having a passageway 13 and carrying a drill bit 14 on its lower end, the drill bit having an opening 15 for passage of drilling fluids from the passageway 13 into the well bore 11 below the assembly.

The drill stem 12` is provided with a first packer 16 having internal reinforcements 17 and 18 on its upper and lower ends and with a Vsecond packer 19 vertically spaced apart from the lirstrpacker and likewise having internal reinforcements 20 'and 21 on its upper and lower ends, AThe packers 16V and 19 are identical with each other. The interior spaces 22 and 23 of the packers 16 and 19, respectively, lfluidly communicate with the inner passageway 13 by longitudinally extending passageways 24 and 25 through ports 26 and "27, the longitudinally extending passageways 24' and' 25 communicating with the inner passageway 13 of thedrill stem y12. in the region or space generally indicated by the numeral 28. Port 24a is provided for deflating the 'packers 16 and 19. v

Slidably arranged inthe drill stem 12 is a piston assembly generally indicated by the numeral 29 and comprised of a piston 30 4having an annular sealing ring 31 and beingV formed of a sleeve 32.y The ,sleeve 32 is vertically extendingand is normally urged by a spring memberr33 to a position which causes theV piston 30 and sealing member 31 to engage sealin'gly with a sealing surface 34 defined by the interior of the drill stem 12 and formed by a ring member 35. The lower end of the spring member 33 rests against a shoulder 36 of the drill stem 12, while the upper end of the spring member 33 rests against a shoulder 37 of the sleeve 32.

it is to be noted that with the piston 30 in the lower position illustrated, the passageways 24 and 25 are in lluid communication with the space 28.

A by-pass conduit or passageway 38 is arranged within the drill stem 12 and communicates by way of a port 59 with the annular space 40 between the borehole 11 and the drill stem 12 above the packer 16 and communicates by a valved port 41 with the space 42 between the packers 16 and 19. The valved port 41 may comprise a check valve 41a provided with a valve member 43 and a spring`44 allowing the valved port 41 to be opened when the pressure in the space 42 exceeds the force of the spring 44.

Retrievably arranged within the passageway 13 of the drill stern 12 is a retrievable tubular sampling assembly 45 which is provided with a lishing neck. 46 on its upper end adapted to be engaged by a fishing tool carried by a wire line for running in the sampling assembly 45 into the drill stem 12 and for retrieving the sampling assembly 45 from the drill stem 12. Sampling assembly 45 is formed to provide a sample chamber 47 which may be closed. on its upper end with a threaded plug 48 which allows the sample to be retrieved from the chamber 47 by way of the reduced passageway 49. The sampling assembly 45 is provided with an inner bore 50 and arranged within the inner bore t) adjacent the sample chamber 47 is a valve member generally indicated by the numeral 51 which serves to close the sample chamber 47. The valve 51 is comprised of a seat member 52 and a valve member 53 urged into seating engagement with the seat member 52 by means of a spring 54 arranged within a tubular member 55 in the inner bore 50. Arranged within a center portion 45a of the sampling assembly 45 is a valve assembly generally indicated by the numeral 56 and comprised of a valve stem 57, a valve seating member 58, pin 4members 59, and a spring member 60. A lateral passageway 61 communicates the valve stem 57 with the annular space 62 between the sampling assembly 45 and the inner wall of the drill stem 12.

The spring member 6i) is in operative engagement with its upper end against the ring 63 of the pin member 59 and is in operative engagement with its lower end against the ring member 64 arranged within the inner bore 5t). The spring member 60, cooperating with the slidable pin .members 59, normally urges the valveV stem 57 against the valve seating member 58, the valve seating member 58 being provided with a sealing surface 65 which sealswith the surface 66 of the valve stem 57.

The inner bore 50 may suitably be provided with a choke member 67 having a restricted, passageway 68 for increasing the pressure within the inner bore 50. The

inner bore 50 below the choke 67 .communicates byway of a lateral passageway 69 with the annular Vspace 62awhich is isolated from the annual space 62 in communication with the passageway 13 and the drilling mud by a rst sealing meanst70, carried by the sampling assembly 45, the isolated annular space 62atbeing isolated on its lower-end by a second sealing means 71 carried by the sampling assembly 45. The sealing meanst7r0 and 71 are engaged with the inner wall of the drill stem to seal o't` the annular space 62 by being expanded by the weight of the sample chamber. These elements are compression-type rubber packers and are forced initially into engagement withA the bore Vof the drillY stem by the weight applied to the sample chamber causing the inside mandrel to 'move downward with respect to the outer case below the packers. When pressure is applied inside the drill stem, it vacts on the upper part of the assemblyto further compress-and expand the packers. The `isolated annular space 62a in turn uidly communicates with the space 42 by a valved port 72 provided with a check valve 73 comprised of a valve member 74 and a spring 75. It is to be noted that the spring 75 is of less strength than the spring 44 such that a sample may be taken and received within the sample chamber 47 before pressure is relieved from the space 42.

Arranged above the valved port 74 is a port or passageway 75a communicating with space 75h which serves to prevent the packer inflation valve assembly 30 from becoming pressure locked.

The lower end of the sampling assembly 45 is provided with a latch 76 comprised of a pin-slot operated dog 77 attached to the sampling assembly 45 by a pin 78. Slot 79 in the dog 77 has a pin arranged therein for movement of the dog 77 from latching to a non-latching position and vice versa. It is to be noted that the sampling assembly 45 has an external shoulder 31 which rests or is supported on the internal shoulder 82 in the drill stem 12. Y i

In obtaining a sample from a formation, such as 9i), pierced by the well bore 11, the sampling assembly 45 would be lowered on a wire line, not shown, to be supported on the surface 32 and then latched with the latching device 76 as shown. The sealing means 70 and 71 are forced out against the wall of the pipe 12 by the weight of the assembly 45 and the space 62a is isolated from the annular space 62 above and below the seals 70 and 71. Thereafter, i'luid pressure would be exerted downwardly in the drill stem 12 through the passageway 13 and through the annular space 62 against the piston 3) which will be designed to move slidably downwardly on exertion of predetermined pressure which will cause the passageways 24 and 25 and space 28 to be placed in uid communication with the area or annulus 62 and allow inliation of the packers .16 and 19 as illustrated. Continued pump pressure would be exerted down through the passageway 13 and on reaching a second predetermined pressure greater than the first predetermined pressure iluid pressure from the amiulus 62 would be exerted through the passageway 61 against the valve stem 57 which presses against the pin member 59 and the spring 66 to move the valve stem olf the seating surface 53 as has been described. Any hydrocarbon contained in the formation 9% then exerts its pressure in the space 42, opening the check valve '73 and allowing the hydrocarbon to ow into the isolated annular space 62a and then by lateral passageway 69 into the inner bore 55 through the open valve assembly 56 and then. upwardly and opening check valve 51 and to be trapped into the sample chamber 47. After a suicient length of time has elapsed to obtain a sample, drilling i'luid pressure will be decreased and the hydrostatic head of fluid in the annulus 40 will cause collapse of the packers 16 and 19 with the drilling iluid accumulated in passages 22 and 23 flowing therefrom through longitudinally extending passageways 24 and 25 and thence outwardly by way of port 24a.

The sampling assembly 45 is then retrieved by engagement of the fishing neck 46 with a wire line fishing tool. By exerting tension on the wire line fishing tool, the latch 76 is disengagedY and the tool retrieved. Thereafter, if the formation 99 Vappears unproductive from the sample trapped in the chamber 47; drilling may then be resumed without the drill stem ever having been pulled from the Well bore.

It will thus be seen that the present invention is of considerable advantage and utility.

The nature and objects of the present invention having been completely described and illustrated, what I wish to claim as new and useful and secure by Letters Patent is: Y l. An off-bottom drill stem-tester which comprises a hollow drill stem with a drill bit on its lower end and provided with an internal supporting means, spaced apart inflatable packers arranged on said drill stem, said drill stern having tirst and second vertically spaced-apart ports betweenthe spaced apart packers communicating the exterior with the interior of the Ydrill stem, saididrill stem being formed to provide longitudinally extending passageways liuidly communicating the interior of each of the spaced apart packers with the interior of the drill stem, a valved piston assembly slidably mounted in said drill stem and movable from a first to a second position and from the second to the tirst position to place, respectively, said longitudinally extending passageways in fiuid communication with the interior of the drill stem to iniiate and in fluid communication with said first port to deiiate said spaced apart packers, a valved sampling assembly retrievably arranged within the drill stem on said supporting means having an inner bore communicating with a valved sample chamber, said retrievable assembly being spaced away from the inner wall of the drill stem to provide an annular space, spaced apart sealing means carried by said retrievable assembly and engageable with the inner wall of the drill stem above and below said second port to isolate a portion of said annular space from said first port, a first passageway in the retrievable assembly fluidly communicating the inner bore with the isolated portion of said annular space, a valve assembly arranged within the inner bore fluidly communicating with the isolated portion of said annular space through a second passageway in the retrievable assembly, said piston assembly moving from its first to its second position on imposition of a first predetermined fiuid pressure on the piston`assembly to inflate said spaced apart packers and close said first port and said valve assembly being openable on imposition of a second predetermined fluid pressure greater than the first lpredetermined pressure to fluidly communicate the inner bore with the sample chamber.

2. An off-bottom drill stem tester which comprises a hollow drill stem with a drill bit on its lower eind and provided with an internal supporting means, spaced apart inflatable packers arranged on said drill stem, said drill stem having first and second vertically spaced-apart ports f between the spaced apartrpackers communicating the exterior with the interior of the drill stem, said drill stem being formed to provide longitudinally extending passageways iiuidly communicating the interior of each of the spaced apart packers with the interior of the drill stem, a valved piston assembly slidably mounted in said drill stem and movable from a first to a second position and from the second to first position to place, respectively, said longitudinally extending pass-ageways in fiuid communication with the interiorfof the drill stem to inflate and in fluid communication with said first port to deflate said spaced apart packers, a valved sampling assembly retrievably arranged within the drill stemvon said supporting means having an inner bore communicating with a valved sample chamber, said retrievable assembly being spaced away from the inner wall of the drill stem to provide an annular space, spaced apart sealing means carried by said retrievable assembly and engageable with the inner wall of the drill stem'above andV below said second port to isolate a portion of said annular space from said first port, a first passageway in the retrievable assembly iiuidly communicating the inner bore with the `isolated portion of `said annular space, ,a valve assembly arranged within the inner bore iiuidly communicating with the isolated portion of said annular space through a second passageway in the retrievable assembly, a by-pass conduit arranged within the drill stem having a firstport `above theupper` of the spaced apartfinliatablepackers and having a second valved port below the upper of the spaced apart packers fluidly communicating with the exterior ofthe hollow drillstem, said piston assembly moving from its rst to its second position on imposition of a first predetermined fluid pressure on the piston member to inate said spaced apart packers and close said first port and said valve assembly `being openable on imposi-A the inner borewith the Asample'chanztber.

v3. An ofi-bottom drill stem tester which comprises a` stern being formed to provide longitudinally extending passageways fiuidly communicating the interior of each of the spaced apart packers with the interior of the drill stem, a valved piston assembly slidably mounted in said drill stem and movable from a first to a second position and from the second to the first position to place, respectively, said longitudinally extending passageways Vin fluid communication with the interior of the drill stem to inflate and in fluid communication with said first port to deflate said spaced apart packers, a valved assembly retrievably arranged within the drill stem on said supporting means having an inner bore communicating vwith a sample chamber, a valve member in said inner bore adjacent the sample chamber vand openable under iiuid pressure in said inner bore to' admit fluid to the sample chamber, said retrievable assembly being spaced away from the inner wall of the drill stem to provide an annular space, spaced apart sealing means carried by said retrievable assembly and engageable with the inner wall of the drill stem above and below Said second port to isolate a portion of said annularr space from said first port,V a first passageway in the retrievable assembly iluidly communicating the inner bore with the isolated por-tion of said annular space, a valve assembly arranged within the inner bore fiuidly communicating with the isolated portion of said annular space through a second passageway in the retrievable assembly, said piston assembly moving from its first to its second position on imposition of a first predetermined fluid pressure on the piston assembly to inflate said spaced apart packers and close said first port and said valve assembly being openable on imposition of a second predetermined fiuid pressure greater thanv the first predetermined pressure to fiuidly cornmunicate the inner bore with the sample chamber.

4. An off-bottom drill stem tester which comprises a hollow drill stem with a drill bit on its lower end and provided with an internal supporting means, spaced apart inflatable packers arranged on said drill stem, said drill stem having first and second vertically spaced-apart ports between the spaced apart packers communicating the exterior with the interior of the drill stem, said drill stem being formed to provide longitudinally extending passageways fluidly communicating the interior of each of the spaced apart packers with the interior of the drill stem, a valved piston assembly slidably mounted in said drill' stem and movable from a first to a second position and from the second to the first position to place respectively saidrlongitudinally extending passageways in Vliuid communication with thel interior of the drill stem to inflate" chamber, said retrievable assembly 'being spacedaway from the inner wall of the drill stem to provide an annular space, spaced apart sealing means carried by said retrievable assembly and engageable with the yinner wall of the drill stem above and below said second port to isol Vlate a portion of said annular space from said rst port,

a first passageway in the retrievable assembly fluidly com- 'municating the inner bore with the isolated portion of said annular space, a valve assembly arranged within the inner bore iiuidly communicating with the isolated portion of said annular space through a second passageway inthe retrievable assembly, said valve assembly comprising a valve stem, a valve seating member, a pin member, and a springmember, said springrmember and pin member urging said valve stemagainst said valve seating -member into inner bore closing position, said piston assembly moving from its tirst to its vsecond position onfimposition of a first predetermined iiuid pressure on the piston assembly to inate said spaced apart packers and close said first port and said valve assembly being openable on imposition of a second predetermined fluid pressure greater than the first predetermined pressure against the valve stern to move the valve stem against the pin member and spring member to open the valve assembly and to tiuidly communicate the inner bore with the sample chamber.

5. An oli-bottom drill stem tester which comprises a hollow drill stem with a drill bit on its lower end and provided with an internal supporting means, spaced apart inliatable packers arranged on said drill stem, said drill stem having first and second vertically spaced-apart ports between the spaced apart packers communicating the exterior with the interior of the drill stem, said drill stem being formed to provide longitudinally extending passageways iiuidly communicating the interior of each of the spaced apart packers with the interior of the drill stem, a valved piston assembly slidably mounted in said drill stem and movable from a first to a second position and from the second to the first position to place, respectively, said longitudinally extending passageways in iiuid communication with the interior of the drill stem to inflate and in fluid communication with said iirst port to deate said spaced apart packers, said piston assembly comprising a piston formed by a slidable sleeve and spring means, said piston being provided with an annular sealing member, said spring means urging said piston into sealing engagement with a sealing surface in said drill stem, a valved assembly retrievably arranged within the drill stem on said supporting means having an inner bore communicating with a valved sample chamber, said assembly being spaced away from the inner wall of the drill stem to provide an annular space, spaced apart sealing means carried by said assembly and engageable with the inner wall of the drill stem above and below said second port to isolate a portion of said annular space from said first port, a first passageway in the retrievable assembly uidly communicating the inner bore with the isolated portion of said annular space, a valve assembly arranged within the inner bore iiuidly communicating with the isolated portion of said annular space through a second passageway in the retrievable assembly, said piston moving from its rst to its second position on imposition of a first predetermined iiuid pressure on the piston to move said annular sealing member from sealing engagement with the sealing surface to inate said spaced apart packers and close said first port and said valve assembly being openable on imposition of a second predetermined iiuid pressure greater than the first predetermined pressure to iiuidly communicate the inner bore with the sample' chamber.

6. An off-bottom drill stem tester which comprises a hollow drill stem with a drill bit on its lower end and provided with an internal supporting means, spacedapart iniatable packers arranged on said drill stem, said drill stem having Iirst and second vertically spaced-apart ports between the spaced-apart packers communicating the exterior with the interior of the drill stem, said drill stem being formed to provide longitudinally extending passageways tiuidly communicating the interior of the spaced-apart packers with the interior of the drill stem, a valved piston assembly slidably mounted in said drill stem and movable from a first to a second position and from the second to the first position to place respectively, said longitudinally extending passageways in liuid communication with the interior of said drill stem to intlate and in tiuid communication with said rst port to deflate said spaced-apart packers, said piston assembly comprising a piston formed by a slidable sleeve and spring means, said piston being provided with an annular sealing meniber, said spring means urging said piston into sealing engagement with a sealing surface in said drill stem, a valved sampling assembly retrievably arranged within the drill stem on said supporting means having an inner bore communicating with a sample chamber, a valve member in said inner bore adjacent the sample chamber and openable under iiuid pressure in said inner bore to admit fluid to the sample chamber, said retrievable assembly being spaced away from the inner wall of the drill stem to provide an annular space, spaced-apart sealing means carried by said retrievable assembly and engageable with the inner wall of the drill stem above and below said second port to isolate a portion of said annular space from said rst port, a tirst passageway in the retrievable assembly uidly communicating the inner bore with the isolated portion of said annular space, a valve assembly arranged within the inner bore liuidly communicating with the isolated portion of said annular space through a second passageway in the retrievable assembly, said valve assembly comprising a valve stem, a valve seating member, a pin member, and a spring member, said spring member and pin member urging said valve stem against said valve seating member into inner bore closing position, a by-pass conduit'arranged within the hollow drill stem having a first port above the upper of the spaced-apart inflatable packers and having a second valved port below the upper of the spaced-apart packers fluidly communicating with the exterior of the hollow drill stem, said piston assembly moving from its first to its second position on imposition of a first predetermined fluid pressure on the piston assembly to move said annular sealing member from sealing engagement with the sealing surface to inflate said spaced-apart packers and to close said tirst pont and said valve assembly being openable on imposition of a second predetermined tiuid pressure greater than the irst predetermined pressure against the valve stem to move the valve stem against the pin member and spring member to open the valve assembly and to tluidly communicate the inner bore with the sample chamber.

References Sited in the tile of this patent Y Stokes Ian. 26, i 

